Which operation creates an equivalent fraction to a/b while keeping its value unchanged?

• A. Swap the numerator and denominator, which results in the reciprocal
• B. Add the same nonzero constant to both numerator and denominator, because adding preserves the value of a fraction
• C. Multiply the numerator by the constant and divide the denominator by the same constant
• D. Multiply both numerator and denominator by the same nonzero constant

Answer: (D)